Process for reducing pickle bloating with dehydroacetic acid

ABSTRACT

1. IN A PROCESS FOR CURING CUCUMBERS IN BRINE BY NATURAL BACTERIOLOGICAL FERMENTATION, WHEREIN THE IMPROVEMENT COMPRISES: THE INCLUSION OF 0.005% TO 0.5% VOLUME OF DEHYDROACETIC ACID IN THE BRINE SOLUTION BASED ON THE TOTAL VOLUME OF BRINE SOLUTION AND CUCUMBERS TO PREVENT GAS AND BLOATING OF SAID CUCUMBER.

United States Patent Office 3,849,579 Patented Nov. 19, 1974 Int. Cl.A23b 7/10 US. Cl. 426-49 3 Claims ABSTRACT OF THE DISCLOSURE In aprocess for the brine curing of cucumbers with salt to make pickleproducts, the improvement comprising using dehydroacetic acid as aprocessing additive in a sufiicient amount to reduce pickle bloatingwhile maintaining yeast growth.

This invention relates to an improvement in reducing the amount ofspoilage in pickle brining processes. More specifically, this inventionrelates to a process and composition for reducing cucumber bloatingduring the brine cure of cucumbers. Cucumbers are typically converted topickle products by brine-curing which is defined hereinafter in thespecification as treating cucumbers with salt and/or salt solutions tocure the cucumber by natural bacteriological fermentation processes.Micro-organisms cause fermentation during the brining process. Thesemicro-organisms essentially come from the cucumbers, their adheringparticles of soil, the tanks themselves, and the brine. The growth ofmicro-organisms during fermentation produces primarily lactic and aceticacids, alcohols, and gases, such as carbon dioxide. The gas from thesemicro-organisms enters or is entrapped by the cucumbers causing bloatingof the cucumbers which results in defective pickles. Bloating is definedhereinafter in the specification to mean the formation or entrapment ofgases or liquids in the cavities or skins of the cucumber frommicro-organisms during the brining process. Bloatings are of twotypesone type being the lens type wherein gas pockets are formed in theindividual cucumber seed carpels and are roughly lens shaped. In aballoon-type bloater, the carpels of the cucumber separate because ofinternal gas pressure and are pressed fiat toward the skin leaving agas-filled or liquid cavity. Bloating results in up to 75 percent of thecucumber stock being spoiled during the brining cure. There has been along-felt need by pickle manufacturers to reduce bloating during thebrining cure. Prior attempts to reduce bloating have been ineffective.

Applicants have discovered that bloating during the brining of cucumberproducts to produce pickle products can be substantially reduced Whilemaintaining the growth of desirable micro-organisms during the naturalfermentation when brining takes place with the use of dehydroacetic acidas a processing additive.

Another aspect of the invention is that dehydroacetic acid in thebrining process was found to be more efficient than typical, expensiveadditive mycostatic agents, such as potassium sorbate. Dehydroaceticacid is effective in reducing bloating in neutral to acid brineconditions.

Potassium sorba'te is effective only in acid conditions and requirestime for the bacteria to produce enough acid to lower the brine pHenough to permit the sorbates mycostatic action. Durin this time, theyeast is producing gases resulting in irreversible defects in thepickles since the yeast can multiply unrestrictedly.

Dehydroacetic acid was found not to contaminate the walls of thepickling tanks with dehydroacetic yeast resistant strain. Hence, whendehydroacetic acid is used, the pickling tanks can be reused withoutcontaminating the walls of the containers which resulted in furtherspoilage.

Dehydroacetic acid at low levels does not hinder yeast growth, butmerely suppresses their gas production which causes pickle bloating.Potassium sorbate suppresses yeast. growth to reduce bloating.Dehydroacetic acid is less expensive than potassium sorbate and only aminor amount relative to potassium sorbate is needed, resulting in lesscost. Another advantage of dehydroacetic acid is that it is odorless andtasteless. Applicants also discovered that low levels of caprylic acidreduced bloating, but resulted in the pickles having an off taste.

In a typical brining process, fresh green cucumbers are added to a largecontainer, tank, or vat wherein they are brined with salt. The amount ofsalt or salt solution varies and is measured in terms of brine salinitywhich is defined as degrees salometer as measured by a hydrometercalibrated in percent of saturation with respect to sodium chloride (0to percent sal.). Degrees salometer are converted to approximateequivalent in percent of salt by weight; for example, 20, 30, and 40sal. brines would approximate brines with 5, 8, and 10 percent of salt.Typically, the amount of cucumbers put into a container ranges from 200to 2,000 bushels and a salt brine of suitable concentration is added tothe brining container. Concentration of the salt added initially usuallyranges from 6 to 12 percent and is increased gradually to 10 to 15percent at the end of four to six weeks. Brining tanks are outdoorsexposed to sunlight; hence the temperature of the brine cure processvaries depending on locality and upon the time of the year. In the Northa lower amount of cucumbers are added to the container vats and thesalting method usually consists of a combination of dry salting andbrine solution.

The initial salt concentration is about 6 to 7.5 percent and is notraised according to any set standard, but is dependent on temperatureconditions and the acid fermentation. Further details on conventionalbrine curing of cucumbers is found in Advances in Cucumber Pickling,Yearbook of Agriculture (1950-1951), by John L. Etchells, Ivan D. Jones,and Thomas Bell, the entire publication of which is hereby incorporatedby reference. During brining, most of the micro-organisms that causefermentation come from the cucumber and adhering particles of soil.During the natural fermentation of cucumbers for salt stock, thefollowing salt tolerant microbial groups are present; acid-formingbacteria (Lactobacillus, Pediococcus), yeast, coliform bacteria, andother halophic bacteria and bacteria of lesser importance. As a resultof the growth of these organisms, lactic acid, acetic acid, and gasesare produced which can result in high pickle bloating. Applicants havediscovered that when dehydroacetic acid was added to the brine solution,pickle bloating was substantially reduced. Dehydroacetic acid reducesthe amount of gas formation by the yeast while not retarding the yeastgrowth. Further details on yeast and bacterial growth is described inAdvances in Cucumber Pickling, pages 9-11 (supra).

The fact that dehydroacetic acid is effective at stopping gas productionby the yeast and does not stop its growth, removes the possibility ofdehydroacetic acid resistant yeast strains being selected in the tankswhich can then act as dehydroacetic resistant yeast cultures which canbecome an inoculum for future cucumber stock in that particular tank.

Dehydroacetic acid is 3 acetyl 6 methyl 1,2- pyran 2,4(3H) dione,otherwise known as methylacetopyronone. The dehydroacetic acid can beadded initially to the salt brine or after the cucumbers are added. Theamount of dehydroacetic acid used ranges from about 0.005 percent to0.50 percent based on total volume of the brine solution and cucumbers.Good results were obtained when 0.005 percent to 0.025 percent was used.Preferred amount is 0.015 percent. Water-soluble salts of dehydroaceticacid can also be used, such as sodium dehydroacetic acid or potassiumdehydroacetic acid.

Dehydroacetic acid was also found to be effective when employed alone orwith other mycostatic agents, such as potassium sorbate, sodiumbenzoate, and caprylic acid, when added to the cushion brine.Optionally, fermentation stimulators can also be added to brine such asyeast extract and mannitol.

Once the cucumbers are salt brined, cured, and have been treated withdehydroacetic acid, various finished pickle products are made fromcompletely cured salt stock (cucumbers) by leaching out the salt,souring with vinegar, or sweetening with sugar.

The following examples show ways in which our invention has beenpracticed, but should not be construed as limiting the invention. Inthis application all temperatures are in degrees Fahrenheit and allparts are parts by weight unless otherwise specified.

EXAMPLE 1 A 45-gallon pickling drum was thoroughly washed with ofdehydroacetic acid and 0.1 percent yeast extract (fermentationstimulator) was added. The amount of defects over percent decreased from16 percent to 8.5 percent.

SUMMARY OF TABLE I The results of Table I showed that when no mycostaticagent was added, 45.6 percent of the pickles had defects of over 20percent in length. When .005 percent dehydroacetic acid was added to thepickling drum, the percent of defects over 20 percent decreased to 33.9percent. When 0.10 percent dehydroacetic acid was employed, the amountof defects over 20 percent decreased to 13.5 percent. When 0.015 percentdehydroacetic acid was added, the amount of defects over 20 percentdecreased to 11.4 percent. When .020 percent dehydroacetic acid wasadded, the defects of over 20 percent were decreased to 17.1 per cent.When potassium sorbate was used, defects under 20 percent were raised to20.0 percent, but defects over 20 percent remained over percent. (Addunder 20 percent defects). Neither dehydroacetic acid nor potassiumsorbate had a significant efiect on honeycomb defect or lens defect.

TABLE I Defects Honey- Pickle DHA, Sorbate, Over Under Lens, comb,Total, Number Example Drum stock percent percent 20% 20% percent percentpercent checked 1 RG 8 0.015 0. 000 11. 4 5.1 9. 3 9. 3 35.1 527 2 RG 80.000 0. 000 45. 6 8. 6 8. 2 5. 8 68. 2 502 3 RG 8 0. 005 0. 000 33. 99. 3 5. 2 7.1 55. 5 496 4 RG 8 0.010 0. 000 13. 5 5. 4 5. 6 4. 0 28. 5496 5 RG 8 0.020 0.000 17.1 21.8 1. 8 1.0 41. 7 510 6 R G 8 0. 025 0.00015. 9 13. 6 2. 3 2.1 33. 9 515 7 R G 8 0. 000 0. 000 50. 8 15.2 7. 7 12.2 85. 9 533 8 RG 8 0.000 0. 03 48. 2 20. 0 7. 3 7. 3 82. 8 519 water andlime, and rinsed. One foot of 44 salometer cushion brine was added tothe pickling drum and 25.5 grams of dehydroacetic acid added. 527 gradeNo. 8 size (large) cucumbers were put into the drum and the drum wasthen filled with brine to cover the cucumbers. This resulted in (0.015percent) dehydroacetic acid by volume of the brine solution andcucumbers. When the lactic acid concentration of the drum reached 0.7percent, adjusted to percent salometer with dry salt, raising it by 2percent salometer per day. After 4 months, the pickles were removed andtested for the amount of bloating.

The amount of bloating was determined by slicing the pickles andmeasuring the length and type of the defects (gaseous hollow portions).The pickles were classified into those having defects of over 20 percentof the longitudinal length of the pickle and those having less than 20percent. The results indicated that only 11.4 percent of the 527 picklestested had defects over 20 percent and 5.1 percent of the 527 picklestested had defects under 20 percent.

The amount of Lens defect was 9.3 percent. Honeycomb defect was 9.3percent (see Table I). Honeycomb defect is defined as when the center ofthe pickle becomes soft and mushy from a series of lens defects. Pickleshaving serious defects have to be used to produce less valuableproducts, such as relish; hence a loss in quality pickle stock isrealized.

EXAMPLES 2-8 For control purposes, pickles were treated in Examples 2-8in the same procedure as in Example 1, except that in Examples 2 and 7,no dehydroacetic acid was added. In Examples 3, 4, 5, and 6 the amountof dehydroacetic acid varied from .005, 0.01, 0.02, and 0.025 percent,respectively. In Example 8, 0.03 percent of potassium sorbate was addedinstead of dehydroacetic acid. The results are shown in Table I.

EXAMPLE 9 The same procedures were followed as in Example 1, except that0.01 percent caprylic acid was used instead Having thus described theinvention, what is claimed is:

1. In a process for curing cucumbers in brine by natural bacteriologicalfermentation, wherein the improvement comprises:

the inclusion of 0.005% to 0.5% volume of dehydroacetic acid in thebrine solution based on the total volume of brine solution and cucumbersto prevent gas and bloating of said cucumber.

2. The process in class 1 wherein said dehydroacetic acid is derivedfrom a water-soluble salt of dehydroacetic acid.

3. The process of claim 2 wherein the salt is selected from sodiumdehydroacetic acid and potassium dehydroacetic acid.

References Cited UNITED STATES PATENTS 2,722,483 11/1955 Winkler 992243,743,519 7/1973 Haas i 99-2 R 2,857,282 10/1958 Jansen 99-156 3,038,810 6/1962 Akerboom et al. 99156 3,255,019 6/1966 Engelland 99-222OTHER REFERENCES I. L. Etchells et al., Influence of Sorbic Acid onPopulations and Species of Yeasts Occurring in Cucumber Fermentations,June 15, 1960.

C. S. Pederson et al., Chemical Abstracts, vol. 61, 15267(a), 1964.

T. Ogawa et al., Chemical Abstracts, vol. 59, 15853g, 1961.

NORMAN YUDKOFF, Primary Examiner C. P. RIBANDO, Assistant Examiner US.Cl. X.R.

1. IN A PROCESS FOR CURING CUCUMBERS IN BRINE BY NATURAL BACTERIOLOGICALFERMENTATION, WHEREIN THE IMPROVEMENT COMPRISES: THE INCLUSION OF 0.005%TO 0.5% VOLUME OF DEHYDROACETIC ACID IN THE BRINE SOLUTION BASED ON THETOTAL VOLUME OF BRINE SOLUTION AND CUCUMBERS TO PREVENT GAS AND BLOATINGOF SAID CUCUMBER.